It is well known that electronic control is becoming commonplace in automobiles, and detecting sensors for detecting the operation of various parts are quite often used. Generally these detecting sensors monitor whether or not the parts are at predetermined positions by using magnetism.
Specifically, multiplexed detecting sensors are responsible for detecting the operation of an important part, such as a part involved in controlling a running automobile. (see JP8-49575A and JP3-491587B). In a multiplexed detecting sensor, a plurality of sensor elements are present, allowing redundancy in the event a malfunction occurs in one of the sensor elements. When one sensor element malfunctions, detection can be performed by using the other sensor element, or detection results of one and the other of the sensor elements are compared to perform failure diagnosis of the sensor elements.
FIG. 14 shows an existing detecting sensor 1 manufactured by the present applicants. The detecting sensor 1 has a magnet 3 with a substantially U shape member and two sensor elements 4A and 4B are held in an housing (not shown). A recess 3a opens on one side of the magnet 3. In the magnet 3, a region A with no magnetic flux exists inside the recess 3a. The two sensor elements 4A and 4B are positioned in the region A with no magnetic flux.
When the detecting sensor 1 is mass-produced, it is important to maintain high location accuracy for the magnet 3 and the sensor elements 4A and 4B. This is because any variations in the positions of the sensor elements 4A and 4B with respect to the magnet 3, directly affect product accuracy when using a plurality of detecting sensors 1.
To address this problem, the magnet 3 and the sensor elements 4A and 4B are fixed to the housing (not shown) of the detecting sensor 1 with high accuracy. However, the sensor elements 4A and 4B are positioned in the housing (not shown) through body members 4e, where an element body and first end of a terminal are embedded.
The disadvantage of this approach is that the body members 4e are molded from insulating resin, and thus do not have high molding accuracy. Therefore, there is a limit to improve the location accuracy of the magnet 3 and the sensor elements 4A and 4B by fixing the sensor elements 4A and 4B to the housing through the body members 4e. 
Location accuracy can be improved by increasing the molding accuracy of the bodies 4e of the sensor elements 4A and 4B; however, such an approach is prohibitively expensive. A need exists for an design that uses an alternative manufacturing method that increases the location accuracy of the magnet 3 and sensor elements 4A and 4B at a low cost.
Further, a disadvantage of the conventional detecting sensor occurs when the object to be detected is a rotating body. When the conventional detecting sensor detects a rotating operation of the object, the magnetic field generated by the magnet is strained by the influence of rotation of the object to be detected, and detection accuracy is affected.